Antiperspirants and Alzheimer's Disease. Back in the 1960s, a few studies found high levels of aluminum in the brains of people with Alzheimer's disease. The research suddenly called into question the safety of everyday household items such as aluminum cans, antacids, and antiperspirants.
A harmonic drive apparatus comprises a circular spline which has internal spline teeth and which is rotatable around a rotational axis , a flexible cylindrical flexspline which is concentrically disposed within the circular spline and which has external spline teeth , the number of flexspline external teeth being less than the number of internal ...
Harmonic. In acoustics and telecommunication, the harmonic of a wave is a component frequency of the signal that is an integral multiple of the fundamental frequency. For a sine wave, it is an integral multiple of the frequency of the wave.For example, if the frequency is f, the harmonics have frequency 2f, 3f, 4f, etc.armonic. In acoustics and telecommunication, the harmonic of a wave is a component frequency of the signal that is an integral multiple of the fundamental frequency. For a sine wave, it is an integral multiple of the frequency of the wave.